Abstract: Pinning phenomenon is a bottleneck constraining operation flexibility of moving bed reactor. Pinning phenomenon and pressure drop were investigated in a trapezoidal cross-flow moving bed model under different operating conditions. The trapezoidal bed model was 1.3 m in height and 0.185 m in top width while 0.299 m in bottom width, the distance between two perspex plates was 0.04 m. Experiments results indicated that pinning appeared before formation of cavity. Pinning thickness and cavity size increased with increasing superficial gas velocity. Their variation with particles mass flux was not evident. Base on the force balance, a mathematical model of pinning was established. The critical pressure drop and pinning thickness could be predicted by this model. The calculation results agreed basically with the experimental data.

Key words: moving bed, pinning, granular materials, powder technology, model

摘要： 贴壁现象是制约移动床反应器操作弹性的瓶颈之一。在高度为1.3 m、顶部宽度为0.185 m、底部宽度为0.299 m、厚度为0.04 m的梯形径向移动床冷模实验装置上考察了颗粒层的贴壁现象。记录不同的操作条件下，贴壁与空腔现象产生的位置及形状大小，并测量了气体通过床层的压降。随着表观气速的增加，贴壁层变厚，空腔变大，呈现为渐进型贴壁；而颗粒循环强度对贴壁与空腔现象无影响。通过力平衡分析建立了梯形床贴壁现象的数学模型，引入矫正因子对模型进行修正，模型计算值与实验值基本相符。

关键词: 移动床, 贴壁, 颗粒物料, 粉体技术, 模型